1、Microbiology of the food chain Enumeration of Brochothrix spp. Colony-count techniqueBS ISO 13722:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Microbiology of the food chain Enumeration of Brochothrix spp. Colony-count techniqueMicrobiologie de la cha
2、ine alimentaire Dnombrement de Brochothrix spp. Technique par comptage des colonies obtenuesINTERNATIONAL STANDARDISO13722Second edition2017-07Reference numberISO 13722:2017(E)National forewordThis British Standard is the UK implementation of ISO 13722:2017. It supersedes BS 7857-3:1997, which is wi
3、thdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/9, Microbiology.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are
4、 responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 90836 1ICS 07.100.30; 67.120.10Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the author
5、ity of the Standards Policy and Strategy Committee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 13722:2017 ISO 2017Microbiology of the food chain Enumeration of Brochothrix spp. Colony-count techniqueMicrobiologie de la chaine alimentair
6、e Dnombrement de Brochothrix spp. Technique par comptage des colonies obtenuesINTERNATIONAL STANDARDISO13722Second edition2017-07Reference numberISO 13722:2017(E)BS ISO 13722:2017ISO 13722:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights
7、 reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from eith
8、er ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 13722:2017ISO 13722:2017(E)ii ISO 2017 All rights reservedCOPYR
9、IGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, wit
10、hout prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgIS
11、O 13722:2017(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Culture media and reagents 26 Equipment and consumables 27 Sampling 28 Preparation of test sample . 39 Procedure. 39.1 Test portion, initial suspension and dilutions 39.2 Inoculation and incubation
12、 39.3 Counting of the colonies . 39.4 Confirmation . 39.4.1 General 39.4.2 Oxidase test 49.4.3 Catalase test . 410 Expression of results 411 Performance characteristics of the method . 411.1 Interlaboratory study 411.2 Repeatability and reproducibility limit . 412 Test report . 4Annex A (normative)
13、Culture media and reagents 6Bibliography 9 ISO 2017 All rights reserved iiiContents PageBS ISO 13722:2017ISO 13722:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International S
14、tandards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, als
15、o take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. I
16、n particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).Attention is drawn to the possibility that some of the elem
17、ents of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations receive
18、d (see www .iso .org/ patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as
19、 well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 9, Microbiology.Th
20、is second edition cancels and replaces the first edition (ISO 13722:1996), which has been technically revised.The main changes compared to the previous edition are as follows: the method specified in this document has been aligned with the NMKL (Nordic Committee on Food Analysis) method described in
21、 Reference 8; the title has been changed from Meat and meat products into Microbiology of the food chain and from Enumeration of Brochothrix thermosphacta into Enumeration of Brochothrix spp., and the scope has been changed accordingly; actidione (cycloheximide) has been omitted from the enumeration
22、 medium because of its toxicity; the catalase test has been added as confirmation test; validation data from an NMKL study8have been included (Clause 11).iv ISO 2017 All rights reservedBS ISO 13722:2017ISO 13722:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide f
23、ederation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that co
24、mmittee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document
25、and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, P
26、art 2 (see www .iso .org/ directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development
27、of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the voluntary nature of
28、standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document
29、 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 9, Microbiology.This second edition cancels and replaces the first edition (ISO 13722:1996), which has been technically revised.The main changes compared to the previous edition are as follows: the method specified in thi
30、s document has been aligned with the NMKL (Nordic Committee on Food Analysis) method described in Reference 8; the title has been changed from Meat and meat products into Microbiology of the food chain and from Enumeration of Brochothrix thermosphacta into Enumeration of Brochothrix spp., and the sc
31、ope has been changed accordingly; actidione (cycloheximide) has been omitted from the enumeration medium because of its toxicity; the catalase test has been added as confirmation test; validation data from an NMKL study8have been included (Clause 11).iv ISO 2017 All rights reserved INTERNATIONAL STA
32、NDARD ISO 13722:2017(E)Microbiology of the food chain Enumeration of Brochothrix spp. Colony-count technique1 ScopeThis document specifies a method for the enumeration of viable Brochothrix spp. by means of a colony-count technique.This document is especially applicable to meat and meat products, bu
33、t is also suitable for the examination of the following: other products intended for human consumption, products intended for animal feeding, environmental samples in the area of food and feed production, handling, and samples from the primary production stage.2 Normative referencesThe following doc
34、uments are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 6887 (all p
35、arts), Microbiology of the food chain Preparation of test samples, initial suspension and decimal dilutions for microbiological examinationISO 7218, Microbiology of food and animal feeding stuffs General requirements and guidance for microbiological examinationsISO 11133, Microbiology of food, anima
36、l feed and water Preparation, production, storage and performance testing of culture media3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Elect
37、ropedia: available at http:/ www .electropedia. org/ ISO Online browsing platform: available at http:/ www. iso. org/ obp3.1Brochothrix spp.Gram-positive bacteria which form characteristic oxidase-negative and catalase-positive colonies on a solid selective medium streptomycin sulfate/thallium aceta
38、te agar (STAA) under the test conditions specified in this documentNote 1 to entry: To date only two species of Brochothrix have been described, Br. thermosphacta and Br. campestris. Br. thermosphacta has often been reported in meat and meat products, but Br. campestris has so far only been identifi
39、ed in samples from soil and grass.9,10The method described in this document cannot differentiate between these two species. ISO 2017 All rights reserved 1BS ISO 13722:2017ISO 13722:2017(E)4 Principle4.1 Surface plating, on a solid selective culture medium contained in Petri dishes, of a specified qu
40、antity of the test sample if the initial product is liquid, or of a specified quantity of the initial suspension in the case of other products. Preparation of other plates, under the same conditions, using decimal dilutions of the test sample or of the initial suspension.4.2 Incubation of the plates
41、 between 22 C and 25 C for 48 h.4.3 Subjection of the colonies to confirmation tests.4.4 From the number of colonies confirmed, calculation of the number of Brochothrix spp. per millilitre or per gram of sample from colonies obtained on plates at dilution levels chosen so as to give the most reliabl
42、e result.5 Culture media and reagentsFollow current laboratory practices as specified in ISO 7218.Carry out the performance testing of culture media as specified in ISO 11133.The composition of culture media and reagents and their preparation are specified in Annex A.6 Equipment and consumablesDispo
43、sable equipment is an acceptable alternative to reusable glassware if it has suitable specifications. Usual microbiological laboratory equipment, as specified in ISO 7218, and, in particular, the following.6.1 Apparatus for dry heat sterilization (oven) or wet heat sterilization (autoclave).6.2 Incu
44、bator or drying cabinet, capable of operating between 25 C and 50 C.6.3 Incubator, capable of operating between 22 C and 25 C.6.4 Petri dishes, made of glass or plastic, of diameter 90 mm to 100 mm.6.5 pH-meter, accurate to within 0,1 pH unit at 25 C.6.6 Spreaders (hockey-stick type), length of appr
45、oximately 20 cm, bent at right angles about 3 cm from one end.6.7 Total-delivery graduated pipettes, of 1 ml nominal capacity, graduated in divisions of 0,1 ml or automatic pipettes.6.8 Water bath, capable of being maintained at 47 C 2 C.6.9 Wires, made of platinum, or rods, made of glass or plastic
46、, approximately 3 mm in diameter.7 SamplingSampling is not part of the method specified in this document. See the specific International Standard dealing with the product concerned. If there is no specific International Standard dealing with the 2 ISO 2017 All rights reservedBS ISO 13722:2017ISO 137
47、22:2017(E)4 Principle4.1 Surface plating, on a solid selective culture medium contained in Petri dishes, of a specified quantity of the test sample if the initial product is liquid, or of a specified quantity of the initial suspension in the case of other products. Preparation of other plates, under
48、 the same conditions, using decimal dilutions of the test sample or of the initial suspension.4.2 Incubation of the plates between 22 C and 25 C for 48 h.4.3 Subjection of the colonies to confirmation tests.4.4 From the number of colonies confirmed, calculation of the number of Brochothrix spp. per
49、millilitre or per gram of sample from colonies obtained on plates at dilution levels chosen so as to give the most reliable result.5 Culture media and reagentsFollow current laboratory practices as specified in ISO 7218.Carry out the performance testing of culture media as specified in ISO 11133.The composition of culture media and reagents and their preparation are specified in Annex A.6 Equipment and consumablesDisposable equipment is an acceptable alternati
